How viruses con bugs into working for them

Washington, Jan 27 (IANS) Some of the viruses are real con artists. They trick new bugs with genetic material filched from their previous bacterial hosts into working for them, reveals a study.

The con occurs when a grifter virus injects its DNA into a bacterium living in a phosphorus-starved region of the ocean. MIT (Massachusetts Institute of Technology) researchers are the very first to document the virus-bacteria relationship.

Such bacteria, stressed by the lack of phosphorus (which they use as a nutrient), have their phosphorus-gathering machinery in high gear. The virus senses the host’s stress and offers what seems like a helping hand: bacterial genes nearly identical to the host’s own that enable the host to gather more phosphorus, the journal Current Biology reported.

The host uses those genes - but the additional phosphorus goes primarily toward supporting the virus’ replication of its own DNA, a university statement said.

Once that process is complete (about 10 hours after infection), the virus explodes its host, releasing progeny viruses back into the ocean where they can invade other bacteria and repeat this process. The additional phosphorus-gathering genes provided by the virus keep its reproduction cycle on schedule.

In essence, the virus (or phage) is co-opting a very sophisticated component of the host’s regulatory machinery to enhance its own reproduction - something never before documented in a virus-bacteria relationship.

“This is the first demonstration of a virus of any kind - even those heavily studied in biomedical research - exploiting this kind of regulatory machinery in a host cell,” said Sallie (Penny) W. Chisholm, professor of civil and environmental engineering and biology at MIT and principal study investigator.